Call transmitter



M R. F. MALLINA CALL TRANSMITTER Fil ed March 22, 1940 4 Sheets-Sheet 2INVENTOR R. F. MALL/NA fine 001% ATTORNEY March 30,1943.

R. E. ALL NA- "pALL TRANSMITTER- Filed March 22, 1940 "4 Sheets-Sheet 3J 435 -43 20 as M mma A FTOR/VE! March 30, 1943;

R. F. MALLINA CALI.- TRANSMITTER v Filed March 22(1940 4 Sheets-Sheet 4INVENTOR I REMALLINAI Patented Mar. 30, 1943 UNITED STATES ATENT QFFICECALL TRANSMITTER Rudolph 1F; Mallina, Hastings on Hudson, N. Y.,

assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y.,a corporation of New York 3 Claims.

This invention relates to call transmitter devices of the type used inautomatic telephone systems, for example, for establishing talkingconnections.

The object of the invention is to improve the construction and operationof such devices.

According to the invention a set of numbered key members is provided foractuating a plurality of bars in predetermined combinations foroperating latch members which normally hold the reeds in pretensionedpositions, the operation of such, latching members and the consequentrelease of the reeds being effective to cause the vibration of thelatter in a magnetic field for generating current voltage ina coilconnected to the telephone line for transmitting signals correspondingto the numbers represented by the operation of the key members.

Means operable upon the placing and removal of the telephone handsetfrom the cradle or switchhook of the substation apparatus is providedfor operating a lever mechanism, the operation of which is effective toactuate a set of switch springs and one of the key bars for causing theoperation of its associated reed for transmitting a signal used forcontrolling the operation of switching apparatus at the telephoneexchange in a manner to differentiate between the telephone calldesignations transmitted and the digits comprised in such designations,such lever mechanism operating a gear train under control of a governormechanism'driven by the tension of a motor spring, to introduce a delaybetween different call designations. Means is also provided foroperating the so-called off-normal contact springs of the transmitter intimed relation to the operation of the reeds as effected by the movementof any one of the key members.

Other novel features and advantages of the invention will appear fromthe following description and by the claims appended thereto, referencebeing had to the accompanying drawings in which:

Fig. l is a top View;

Fig. 2 is a top assembly view shown with the casing in section} Fig. 3is a side elevation view shown with the base and the casing in section,the transmitter mechanism being shown in normal non-operated position;

Fig. 4 is a detail view showing the off-normal switch springs and theirattuating mechanism;

Fig. 5 is a view similar to that of Fig. 3 showing the speed governordriving mechanism in the operated position and the handset shown indotted lines in position in the cradle of the casing;

Fig. 6 is a left side elevation view showing the reeds operating andreleasing mechanism in normal unoperated position;

Fig. 7 is a fragmentary View showing one of the keys partly operated;

Fig. 8 is a view similar to Fig. 7 showing one of the keys and a latchmember in the operated position, a reed being shown released;

Fig. 9 is a fragmentary view showing the operative combinations of thebars with the key members;

Fig. 10 is a perspective view showing the sets of switching springs andtheir actuating mechaand B5 are pivotally mounted, while retractilesprings such as 26 best seen in Figs. 2,10 and 11 are hooked at one oftheir ends to the upright extending portions 2'7. of plate 22 and theirother ends to the respective keys KI, K2, K3, etc, to serve foryieldably holding these keys in their normal non-operated positions asshown in Figs. 1, 2, 3, 5, 10 and 11, the U-shaped bars Bl, B2, B3,

B and B5 being in turn yieldabl'y held in their normal unoperatedpositions by retractile springs 28 having one of their ends hooked tothe upright extending portion 21 of plate 22 and their other ends tolugs 29 formed with lever members 39, 3E, 32, 33 and 34 secured to theU-shaped bars Bl, B2, B3, B4 and 135 respectively, as by rivets rt.

'Each lever member 30, 3|, 32, 33 and 34 is formed with similar lugportions 35 and 36 best seen in Figs. 6, 7, 8 and 11, provided for apurpose which will be hereinafter described in detail. On plate 22 ismounted a so-called voltage generator consisting of a permanent magnetformed of two pole-pieces 40 cooperating with a plurality of screws SCfor clamping a plurality of reeds El, R2, R3, R4 and R5 therebetween.These reeds extend through the central opening of a coil 5| connected tothe telephone line in engageable relation with lugs 36 provided formoving these reeds in normal flexed position as shown in Fig. 6, whileribbon springs as 43 carried by lever members 33, 3|, 32, 33 and 34cause the pivotal movement of pawls aI bl, cl, cZI and (BI for movingthem in position for retaining their associated reeds RI, R2, R3, R4 andR5 flexed following the partial movement of the bars BI, B2, B3, B4 andB5 as efiected by the key members KI, K2, K3, etc., for a purpose whichwill be hereinafter described in detail, the operation of the bars BI,B2, B3, etc., by the key members KI, K2, K3, etc., being effected in thefollowing combinations:

Key Kl. actuates the U-shaped bars BI and B2 operatively associated withthe reeds RI and R2;

Key K2 actuates the bars B2 and B3 operatively associated with the reedsR2 and R3;

Key K3 actuates the bars BI and B3 operatively associated with the reedsRI and R3;

Key K4 actuates the bars 133 and B4 operatively associated with thereeds R3 and R4;

Key K5 actuates the bars B5 and B3 operatively associated with the reedsR5 and R3;

Key K6 actuates the bars B2 and B4 operatively associated with the reedsR2 and R4;

Key K'I actuates the bars BI and B5 operatively associated with thereeds RI and R5;

Key K8 actuates the bars BI and B4 operatively associated with the reedsRI and R4;

Key K9 actuates the bars B5 and B2 operatively associated with the reedsR5 and R2; and

Key Klfl actuates the bars B4 and B5 operatively associated with thereeds R4 and R5, thus actuating the reeds RI, R2, R3, R4 and R5 in tendifferent combinations.

The U-shaped bar B6 which is pivotally mounted on shaft 25 is held inoperable relation with each of the key members KI, K2, K3, etc., by aretractile spring 45 shown in Figs. 2, 3, 4, 10 and 11 hooked at one endto an arm 46 carried by that bar and its other end hooked to the upwardextending portion 21 of plate 22. The arm 45 is provided with a downwardextending portion 41, best seen in Fig. 4, carrying a stud 48 made ofinsulating material provided for actuating a set of switch springs 49mounted in a pile-up arrangement on the plate 22 and held securelythereon by screws 53 and 5| shown in Fig. 2, the function of switchsprings 49 being to effect circuit connections similar to the so-calledoff-normal contacts as used in ordinary finger-wheel operated calltransmitters.

The pawls aI, bI, cl, (1! and eI are pivotally mounted on similarright-angle-shaped brackets 54, best seen in Figs. 6, 7 and 8, havingtheir horizontally disposed sides secured on the permanent magnet 40 byscrews 55, while nuts 56 engaging the studs 51 also mounted on magnet 43are provided for adjusting these pawls to permit their movement inposition under the free ends of reeds RI, R2, R3, R4 and R5 when thelatter are moved in their normal flexed positions as shown in Fig. 6.

The U-shaped bar B5 carries an arm 5-8 shown in Figs. 2, 3, 5, 9 and 10having its free end disposed in 'engageable relation with the arm a2 ofa yoke member pivoted on a shoulder screw BI laterally extending from aflange 53 secured to the plate 22, while the opposite arm (13 of thisyoke is disposed in operable relation with an arm 52 formed with apivoted plate 53 operated by gravity against the tension of a retractilespring 69 upon the placing of the telephone handset on the ends of studs54 and 65 shown in Figs. 1, 3, 5 and 6 extending in bearings in thecradle CF of a casing 2i which in cooperation with the base 20 servesfor housing the transmitter mechanism,

the plate 63 being pivoted on a shaft 61 supported at both ends by abracket 65 securely mounted on studs 68 laterally extending from thebase 20.

The yoke member in addition to arms (22 and a3 is formed with adownwardly extending arm a4 operatively engaging a lever member I3mounted on a shaft II. This shaft is journaled at one end on the flange60 and at its other end in a plate I2 extending perpendicularly to plate22 and secured thereto by screws I3 shown in Figs. 2, 3 and 10, and onshaft II is securely mounted a gear sector I4 meshing with the pinion I5mounted on a shaft I6 for rotation with a gear 11, in turn engaging apinion I8, mounted on a shaft I9, for rotating a fan-wheel serving as aspeed governor for controlling the operation of gear sector I4 aseffected by a spring 8i having one end connected to an arm :15 of theyoke and its other end connected to a lug 83 formed with the gear sectorI4 and tensioned by the pivotal movement of plate 63 upon the placing ofthe telephone handset in its cradle and the conconsequent operation ofplungers 64 and 65 as above described, the rotation of gear sector I4from the position shown in Fig. 3 to the position shown in Fig. 5 beingeffective to actuate the switch springs 84 to perform switchingoperations so as to permit the automatic switches at the telephoneexchange to operate in a manner to distinguish between digits andcomplete call designations transmitted.

In a typical example of operation supposing that it is desired totransmit the call designation EBB-4627. Upon the removal of thetelephone handset from its cradle CF the spring 69 shown in Figs. 2, 3,5, 6, 10 and 11 is effective to cause the pivotal movement of plate 63from the position shown in Fig. 5 to the position shown in Fig. 3; andthereby causing the clockwise pivotal movement of the yoke under thetension of retractile spring 28 of bar B5 and that of the shaft IIthrough the engagement of lever I3 with the arm a4 of the yoke. Thepivotal movement of arm I0 permits the contact spring 84A to open itsupper contacts and close its lower contacts under the medium of its owntension while the yoke through its arm (12 permits the upward movementof arm 58 and, therefore, the movement of U-shaped bar B5 as effected byits retractile spring 23 from the position shown in Fig. 5 to theposition shown in Fig. 3 for tensioning its associated reed eI prior tothe operation of any one of the key members KI, K2, K3, etc. Theoperation of key K3 for transmitting the letter E, the first digit ofthe call designation EH3-4627 above-mentioned is effective to impart asmall angular movement to U-shaped bar BI carrying lever 34 and to barB3 carrying lever 32. A partial pivotal movement of these levers fromthe position shown in Fig. 6 to the position shown in Fig. 7 permits thereeds RI and R3 to move in abutment against the ends of the upwardextending portions of their associated pawl-like members al and cl sothat upon the continued movement of the key K3, the lugs 35 of levers 34and 32 engage their respectively associated pawls al and cl for pivotingthem from the position shown in Figs. 6 and '7 to the position shown inFig. 8 for releasing the reeds RI and R3 simultaneously and therebycausing their vibrations. The operation of key K3 in addition to therelease of the reeds RI and R3 is effective to impart a pivotal movementto the U-shaped bar 136 against the tension of its retractile spring 45(see Fig. 3) for operating the set of off-normal contact springs 49through the insulating stud 48 carried by th downward extending lugportion 41 of arm 46 secured to that bar. The return movement of key K3in normal position under the tension of its retractile spring 26following its release by the operator, and the consequent returnmovement of the U -shaped bars BI and B3 under the tension of theirretractile springs 28 is effective to move their associated reeds RI andR3 in the pretensioned position and this operation repeated for each ofthe keys included' in the call designation EH3-4627 abovementioned butaccording to the operating combinations above described.

The placing of the telephone handset in its cradle following the sendingof the call designation causes the downward movement of plungers 64 and65, the pivotal movement of plate 53 from the position shown in Fig. 3to the position shown in Fig. 5 against the resistance of its retractilespring 69 and the counter-clockwise movement of the yoke actuatedthereby for causing the pivotal movement of U-shaped bar B5 and theconsequent vibrations of reed R5, while the movement of the yoketensions the spring 8| which rotates the gear sector 14 under control ofthe fan-wheel 8D geared thereto for operating the spring 84A for openingits lower contact and closing its upper contact as shown in Fig. 5 a

small fraction of time after the operation of reed R5, and thetransmitter is now ready for a subsequent call transmitting operation,the function of contact springs 84 being to permit the automatic switchcontrolled thereby to return to nor mal position preliminary to asucceeding call transmitting operation.

What is claimed is:

1. A call transmitter device for a telephone desk set, said desk setcomprising a handset, plunger members, a pivoted plate actuated by theplacing of the handset on the plunger members, in combination with a setof manually operable key members for the transmitter, a plurality ofvibrative reeds, a plurality of means actuated in predeterminedcombinations by the operation of said key members to cause the operationof said reeds, a set of ofi-normal contact springs, a lever mechanismoperated by the placing of the handset on the plunger members foractuating the contact springs and one of said reeds independently of theoperation of its associated key member, a gearing mechanism actuated bysaid lever mechanism, and a speed governor. operatively connected tosaid gear mechanism for producing a time delay between the operation ofthe lastmentioned reed and the operation of said contact springs.

2. A call transmitter device for a telephone desk set, said desk setcomprising a handset, plunger members, a pivoted plate actuated by theplacing of the handset on the plunger members, in combination with a setof manuallyoperable key members for the transmitter, a plurality ofvibrative elements, a plurality of means actuated in predeterminedcombinations by the operation of said key members to cause the operationof said elements, a set of contact springs, a lever mechanism operatedby the placing of the handset on the plunger members for actuating thecontact spring and one of said elements independently of the operationof its associated key member, a motor spring tensioned by the operationof said lever mechanism, a governor mechanism actuated by the tension ofsaid motor spring for'retarding the operation of the contact springsrelative to the operation of said element by one of said means, saidlever mechanism comprising a lever carried by the last-mentioned means,a pivoted yoke having an arm engaging said lever and its other armengaging said pivoted plate, a third arm disposed in operative relationwith said governor mechanism for tensioning said motor spring foractuating said contact springs and said governor following the movementof said plate and thereby one of the vibrating elements in one of saidcombinations.

3. A call transmitter device having a set of onnormal switch springs, aset of manually operable

